Solar systems have been available for residential and commercial use in various forms for a long time. Adoption of modern technologies has led to systems which can be installed on rooftops to deliver a rated 1 kW or 2 kW power output (for example). Likewise, systems can be installed which provide hot water for household use or for heated swimming pools.
Consumers typically must proactively seek their own alternatives to utility-provided electricity. This typically requires a significant investment in time & effort on the part of the consumer to learn about renewables, and then specifically solar options, to seek out providers (installers) and then to select and proceed with purchasing a system. Whether this involves self-installation or installation by a contractor, consumer self-education is a typical requirement.
Solar power and water systems generally do not have a standard design. Given the extreme variations in houses, this is not surprising. However, this means that every installation is unique. Not only is every installation unique, but standard products which may be used time and again on multiple installations are generally not available. Moreover, this leads to interesting and unusual situations, with extension cords snaking across roofs or water pipes running up and down from an external swimming pool to the roof of a house. With every installation a one-off design, economies developed from one design to the next are reduced. Thus, providing a standard design with components which are well organized for varying installations may be useful.
The solar power systems are rated for a specified output, but are not expected to actually deliver that output. Perversely, most government subsidy programs rely on a system rating rather than actual output for incentives. Actual output can have an effect down the road, when the user's power bill comes due, but it is not a significant part of the analysis initially. It may still be useful to develop a system which can be installed with a guarantee of how much power will be output on average.